CALIFORNIA w Water Boards ENVIRONMENTAL PROTECTION€¦ · CALIFORNIA w Water Boards ENVIRONMENTAL PROTECTION Los Angeles Regional Water Quality Control Board December 10,2012 Mr

C A L I F O R N I A w Water Boards ENVIRONMENTAL PROTECTION

Los Angeles Regional Water Quality Control Board

December 10,2012

Mr. Enrique C. Zaldivar, Director Department of Public Works, Bureau of Sanitation City of Los Angeles 1149 South Broadway Street, gth Floor Los Angeles, CA 9001 5-221 3

Dear Mr. Zaldivar:

ADOPTED TIME SCHEDULE ORDER (TSO) NO. R4-2012-0180 - CITY OF LOS ANGELES, DONALD C. TILLMAN WATER RECLAMATION PLANT (NPDES NO. CA0056227, CI NO. 5695)

Our letter dated November 13, 2012, transmitted the tentative ammonia TSO directing Donald C. Tillman Water Reclamation Plant to comply with its National Pollutant Discharge Elimination System (NPDES) permit and Waste Discharge Requirements (Order No. R4-2011-0196), adopted by the Regional Water Board on December 8,201 1.

Pursuant to Division 7 of the California Water Code, this Regional Water Board at a public hearing held on December 6, 2012, reviewed the tentative requirements, considered all the factors in the case, and adopted Order No. R4-2012-0180 (copies enclosed) for your waste discharge.

The expiration date and all other provisions and requirements of Order No. R4-2011-0196 are unchanged and shall remain in full force and effect.

The final Order will be sent only to the City of Los Angeles. However, the document is available on the Regional Water Board's website for public review. The Regional Water Board's web address is www.waterboards.ca.aov/losanqeles/. ,

Please continue to submit electronic self-monitoring reports (eSMRs) using the State Water Board's California Integrated Water Quality System (CIWQS) Program website 7

(http://www.waterboards.ca.~ov/ciwqs/index. html).

If you have any questions, please contact Elizabeth Erickson at (21 3) 576-6665. R

320 West 4th St., Suite 200, Los Angeles. CA 90013 1 www.waterboards.ca.gov/losangeles

a RECYCLED PAPER

Mr. Enrique Zaldivar City of Los Angeles

I Enclosure

cc:

December 10,2012

United States Environmental Protection Agency, Region 9, Permits Branch National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries

Service Department of Interior, United States Fish and Wildlife Service State Water Resources Control Board, Office of Chief Counsel California Department of Fish and Game, Region 5 California State Parks and Recreation California Coastal Conservancy Los Angeles County, Department of Power and Water, Watershed Division Los Angeles County, Department of Health Services Water Replenishment District of Southern California Main San Gabriel Basin Watermaster Heal the Bay California Association of Sanitation Agencies (Tri-TACICASA) Environment Now Santa Monica Baykeeper Natural Resources Defense Council Friends of the Los Angeles River Los Angeles and San Gabriel Rivers Watershed Council Sierra Club San Gabriel and Lower Los Angeles Rivers and Mountains Conservancy

STATE OF CALIFORNIA CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD

LOS ANGELES REGION

TIME SCHEDULE ORDER NO. R4-2012-0180

REQUIRING CITY OF LOS ANGELES (DONALD C. TILLMAN WATER RECLAMATION PLANT) TO COMPLY WITH REQUIREMENTS PRESCRIBED IN

ORDER NO. R4-2006-0091 (NPDES PERMIT NO. CA0056227)

i The California Regional Water Quality Control Board, Los Angeles Region (Regional Water Board) finds:

I 1. The City of Los Angeles (City) owns and operates the Donald C. Tillman Water Reclamation Plant (Tillman WRP), a tertiary wastewater treatment plant located at 61 00 Woodley Avenue, Van Nuys, California.

2. The Tillman WRP discharges tertiary-treated wastewater under waste discharge requirements contained in Order No. R4-2006-0091, adopted by this Regional Water Board on December 14, 2006. Order No. R4-2006-0091 serves as a permit under the National Pollutant Discharge Elimination System (NPDES No. CA0056227) and regulates the discharge of treated wastewater to Los Angeles River, a water of the United States and the State of California, within the Los Angeles River Watershed. Order No. R4-2006-0091 expired on November 10, 2011.

3. On January 25, 2010, the Regional Water Board entered into a settlement agreement with the City in an effort to resolve lawsuits and petitions challenging the 1998 Permit (Order No. 98-046) and 2006 Permit (Order No. R4-2006-0091). The settlement agreement required that a variety of negotiated modifications to Order No. R4-2006-0091 be brought before the Regional Water Board for its consideration. The settlement agreement did not bind the Regional Water Board's judgment in consideration of those modifications, but the modifications did reflect staff recommendations. Order No. R4-2010-0060 adopted by this Regional Water Board on April 1, 201 0, modifying Order No. R4-2006-0091, 'was the result of the public hearing on staff's proposals pursuant to the settlement agreement.

4. The Regional Water Board adopted a revised permit (Order No. R4-2011-0196) for the Tillman WRP at its December 8, 2011 hearing. R4-2006-0091 and R4-2010- 0060 expired on February 3, 2012, the effective date of the Order No. R4-2011- 01 96.

1

October 1,2012 Revised November 5,201 2

City of Los Angeles Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

NPDES No. CA0056227

5. The treatment system of the Tillman WRP consists of grit removal, screening, flow equalization, primary sedimentation, nitrification and denitrification (NDN') activated

I sludge biological treatment with fine pore aeration, secondary clarification, coagulation, aqua diamond cloth filtration, disinfection by chlorination with the addition of ammonium hydroxide to form chloramine, and dechlorination.

6. Order Nos. R4-2006-0091, R4-2010-0060 and R4-2011-0196 prescribe the final effluent limitations for ammonia listed in Table 1 for protection of aquatic life in the receiving water of the Los Angeles River:

I The ammonia effluent limitations for monthly average and daily maximum (1.4 mg/L and 4.2 mg/L, respectively) are based on the waste load allocations (WLAs) in the Los Angeles River Nitrogen Compounds Total Maximum Daily Loads (LA River Nitrogen Compounds TMDLs). These limitations have been. effective since October 1, 2007, after the incorporation of the NDN process at Tillman WRP.

The previous NPDES permit regulating the discharge of treated wastewater from the Tillman WRP, Order No. 98-046, did not contain any ammonia effluent limitations.

Table 1. Ammonia Effluent Limitations

7. The section 303(d) list of impaired waterbodies in California, as approved by the United States Environmental Protection Agency (USEPA), identifies ammonia as impacting the Los Angeles River, the receiving water for the Tillman WRP.

Constituent

Ammonia

! 8. In 2003, the cities of Los Angeles and Burbank and the Sanitation Districts of Los Angeles County completed and submitted site-specific objective (SSO) study for ammonia in the Los Angeles River, the San Gabriel River, and the Santa Clara River watersheds. On June 7, 2007, the Regional Water Board adopted Resolution No. 2007-005, Amendments to fhe Water Quality Confrol Plan-Los Angeles Region fo Incorporate Sife-Specific Objectives for Selecf Inland Surface Wafers in fhe San Gabriel River, Los Angeles River and Sanfa Clara River Watersheds. The Basin Plan amendment incorporated the results of the study as site-specific 30-day average objectives for ammonia along with corresponding site-specific early life stage implementation provisions. The State

- -- --

I In order to achieve compliance with the ammonia water quality objectives (WQOs) specified in the Water Quality Control Plan for the Los Angeles Region (Basin Plan), the City began to test different NDN treatments, including Modified Ludzack-Ettinger Process, Enhanced Modified Ludzack-Ettinger Process, and Step-Feed Process. The City completed construction of the NDN treatment facility in September 2007, and took 90 days to optimize operation of the NDN facilities.

Unit

mg/L

Effluent Limitations

Monthly Average

I .4

Daily Maximum

4.2


NPDES No. CA0056227

Water Resources Control Board (State Water Board), the California Office of Administrative Law (OAL), and USEPA approved the amendment on January 15, 2008; May 12, 2008; and March 30, 2009, respectively.

To date, the LA River Nitrogen Compounds TMDLs has not been revised to

i incorporate the ammonia SSO. Until the TMDL is revised, the permit for the Tillman WRP cannot be revised to incorporate the ammonia SSOs.

9. On November 10, 2011, the City submitted a letter to the Regional Water Board requesting a Time Schedule Order (TSO) for the average monthly ammonia effluent limitations. The City listed the following as the reasons to justify their request:

I

A. Attainability of ammonia effluent limitations is challenging.

Compliance with the ammonia limits has proven to be challenging because of the nature of, and the requirements for, the operation of the NDN process and the need to comply with other effluent limitations that are inversely impacted by ammonia concentrations in the effluent. For example, the nitrification processes have the capability to remove the majority of ammonia present in the influent to the Tillman WRP. However, ammonia must be added back into the effluent prior to the disinfection process to reduce the formation of trihalomethanes. As a result, compliance with the effluent limits is uncertain and is not sustainable on a long-term basis, and the probability of exceeding the ammonia effluent limitations is likely.

B. Ammonia analysis is infeasible.

The City needs to pursue alternative control measures to ensure long-term, sustainable compliance with the ammonia effluent limitations. These alternatives could include modifications to the operations of the Tillman WRP, further evaluation of technology for real-time ammonia monitoring, or modifications to the disinfection process. In order to determine the best long-term solution to this complex issue, the City needs time to evaluate the available options.

C. Ammonia SSOs in the Basin Plan amendment shall be applied.

Until the LA River Nitrogen Compounds TMDL targets and WLAs have been revised to reflect the revised ammonia objectives now that the SSOs are in effects, the ammonia effluent limitations in the NPDES permit for the Tillman WRP must be set equal to the existing TMDL ammonia WLAs.

10. TSO No. R4-2012-0007 was issued by the Executive Officer on February 2, 2012, following a 30 day public review. TSO No. R4-2012-0007 expired on October 1, 2012.


NPDES No. CA0056227

11. On August 22, 2012, the City submitted a letter (via email) to the Regional Water Board requesting an extension of TSO No. R4-2012-0007, for the following reasons:

A. Ammonia additions to control trihalomethanes.

The NDN addition, completed in 2007, effectively removes most ammonia from the effluent; however, ammonia must be added back into the effluent prior to the disinfection process to reduce the formation of trihalomethanes.

B. Incorporation of Basin Plan Amendment into LA River Nitrogen Compounds TMDLs (See Finding No. 8 above).

Until the LA River Nitrogen Compounds TMDLs are revised to incorporate the Basin Plan WQOs, the Tillman WRP NPDES permit cannot be revised to incorporate the ammonia SSO. The Tillman WRP ammonia effluent limits are currently set equal to the existing TMDL WLAs without an adjustment for the Basin Plan ammonia objectives.

C. TSO Compliance Activities

Per section 13300 and 13385(j) of the California Water Code and in compliance with the Tillman WRP's NPDES permit, the City has submitted specific actions in order to achieve full and consistent compliance with ammonia WQOs. The City's staff has researched and performed the following compliance activities:

a. Calibrated, relocated, and tested Tillman WRP1s secondary effluent ammonia analyzer which allows better control over ammonia addition during the disinfection process;

b. Researched the feasibility of utilizing new wet-chemical process ammonia analyzers;

c. Reviewed Standard Operating Procedures for ammonia addition;

d. Trained operations staff on secondary effluent ammonia analyzer operation procedures as a tool to achieve enhanced control of ammonia addition during the disinfection process;

e. Investigated different hypochlorite and ammonia addition ratios during the disinfection process and during different ambient temperature levels; and,

f. Contacted ammonia analyzer vendors to investigate newer product offerings for low-level detection (in the past, low-level testing of product offerings has showed iilconsistent and problematic results).

City of Los Angeles NPDES No. CA0056227 Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

D. Future Testing and Studies

The City will continue to optimize hypochlorite and ammonia addition during the disinfection process while attempting to maintain full compliance with ammonia effluent limits. Because the current TSO No. R4-2012-0007 expires on October I , 2012, the City needs more time to test the optimum dosage during different seasons, particularly during the winter months when microbial activity is slower.

12. Section 13300 of the Water Code states:

"Whenever a regional board finds that a discharge of waste is taking place or threatening to take place that violates or will violate requirements prescribed by the regional board, or the state board, or that the waste collection, treatment, or disposal facilities of a discharger are approaching capacity, the board may require the discharger to submit for approval of the board, with such modifications as it may deem necessary, a detailed time schedule of specific actions the discharger shall take in order to correct or prevent a violation of requirements."

13. The Regional Water Board made the following finding in TSO No. R4-2012-0007:

A. Based on a review of monitoring data, although the City has not yet violated the effluent limitations, they have been very close, and may not consistently achieve compliance with the final average monthly effluent limitations for ammonia in Order Nos. R4-2006-0091 and R4-2010-0060. Accordingly, pursuant to Water Code section 13300, a discharge of waste is taking place andlor threatens to take place that violates requirements prescribed by the Regional Water Board.

14. Current monitoring data of effluent from the Tillman WRP shows that the City is still challenged to comply with the current ammonia monthly average effluent limitation (1.4 mgIL), See Table 2. In addition, based on the result of the normal distribution probability plot of 54 data using Minitab 14, it is anticipated that ammonia effluent concentrations in the discharge may exceed the monthly average effluent limitation of 1.4 mg1L 15 percent of the time.

Table 2. Ammonia Effluent Concentrations

Ammonia Concentration Ranges (mg/L)

Number of Monitoring Results (Jan 2008 to

June 2012)


NPDES No. CA0056227

Accordingly, pursuant to Water Code section 13300, a discharge of waste is taking place and/or threatens to take place that violates requirements prescribed by the Regional Water Board.

Ammonia Concentration Ranges (mg/L)

0.9 - 1 .O

0.8 - 0.9

0.0 - 0.8

15. Water Code section 13385, subdivisions (h) and (i), require the Regional Water Board to impose mandatory minimum penalties upon dischargers that violate certain effluent limitations. Section 13385(j)(3) exempts violations of an effluent limitation from mandatory minimum penalties "where the waste discharge is in compliance with . . . a time schedule order issued pursuant to Section 13300, if all of fhe [specified] requiremenfs are mef. " (emphasis added).

Number of Monitoring Results (Jan 2008 to

June 2012)

5

2

2

16. In accordance with Water Code section 13385(')(3)(B), mandatory minimum penalties do not apply to a violation of an effluent limitation where the waste discharge is in compliance with a time schedule order issues pursuant to Section 13300 or 13308; the effluent limitation is a new, more stringent limitation that became applicable after adoption of the prior permit; new or modified control measures are necessary in order to comply with the effluent limitation; and the new or modified control measures cannot be designed, installed, and. put into operation within 30 calendar days.

17. The Regional Water Board made the following findings in TSO No. R4-2012-0007:

A. The effluent limitations for ammonia in the 2006 permit for the Tillman WRP (Order Nos. R4-2006-0091 and R4-2010-0060) incorporate the LA River Nitrogen Compounds TMDL's ammonia WLAs. The effluent limitations for ammonia became effective on October 1, 2007. The previous permit (Order No. 98-046) did not include effluent limitations for ammonia.

B. It was necessary for the discharger to implement new or modified control measures to comply with the new effluent limitation in the 2006 permit, which control measures could not be designed, installed, and put into operation within 30 calendar days.

C. Municipal wastewater treatment plants are complex systems, involving multiple biological and chemical processes. The control of ammonia in particular can have impacts on concentrations of other constituents in the effluent. The NDN process installed at the Tillman WRP has the capability to

City of Los Angeles '

Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

NPDES No. CA0056227

remove the majority of ammonia present in the influent to the plant. However, ammonia must be added back into the effluent prior to the disinfection process to reduce the formation of trihalomethanes. Technology is not currently available to allow sufficient real-time monitoring of ammonia to optimize the ammonia add-back process.

D. The NDN facilities were designed to treat the entire design capacity of the Tillman WRP; however, due to disinfection requirements and to meet the Tillman WRP's concentration-time requirements, the Tillman WRP continues to treat less flow than the design capacity. As the Tillman WRP increases flow, the impact on the NDN process and ammonia add-back requirements is more uncertain.

E. Based on this analysis and the operational issues discharged above, the City must pursue alternative control measures to ensure long-term, sustainable compliance with the monthly average effluent limit for ammonia. These alternatives could include modifications to the operations of the Tillman WRP, further evaluation of technology for real-time ammonia monitoring, or modifications to the disinfection process. In order to determine the best long-term solution to this complex issue, the City needs time to evaluate the available options and to implement alternative control measures to consistently comply with the effluent limitations for ammonia. Pursuant to Water Code section 13385(j)(3)(B)(iii), new or modified measures to control the composition of the waste discharge cannot be designed, installed, and put into operation within 30 calendar days.

18. Water Code section 13385(j)(3)(C) states that following a public hearing, and upon a showing that the discharger is making diligent progress toward bringing the waste discharge into compliance with the effluent limitation, the regional board may extend the time schedule for an additional period not exceeding five years in length, if the discharger demonstrates that the additional time is necessary to comply with the effluent limitation.

The City has made diligent progress toward bringing the waste discharge into compliance with the, effluent limitations for ammonia by taking those actions described in Finding No. 11 .C. The City has demonstrated that additional time is necessary to comply with the effluent limitations for ammonia to pursue alternative control measures to ensure long-term, sustainable compliance with the ammonia effluent limitations. These alternatives could include modifications to the operations of the Tillman WRP, further evaluation of technology for real-time ammonia monitoring, or modifications to the disinfection process.

19. When issuing TSO No. R4-2012-0007, the Regional Water Board staff considered three options for calculating interim ammonia monthly effluent limitations (as summarized in Table 3), based on effluent and receiving water monitoring data collected between January 1, 2008 and March 31, 201 1. Interim ammonia monthly


NPDES No. CA0056227

effluent limitations of 1.6 mg/L and 1 .I mg/L, based on the 95 percentile of effluent performance and a recalculation of the ammonia water quality objectives (as proposed by the City), respectively, will not help the City to avoid potential effluent violations. In addition, Heal the Bay disagrees with increasing the interim ammonia effluent limitation as high as would be allowed by the Ammonia SSO procedure, ranging from 4.6 mg/L to 6.1 mg/L. Consequently, this TSO assigns the interim ammonia monthly effluent limitation to be 2.2 mg/L, equal to the final ammonia effluent limitation for the Los Angeles-Glendale Water Reclamation Plant. This limit is protective of aquatic life and attainable by the City.

Table 3. Ammonia Interim Monthlv Effluent Limitations

im Monthly Effluent mitations (mg/L)

1 95 Percentile (Performance-based) I 1 .62 I Ammonia SSO (Effluent Data-based)

Discharge Points 001, 002, and 003

Discharge Point 008 I I

April 1 - September 30

October 1 - March 31

4.63

6.1

Ammonia SSO (Receiving Water Data-based)

Discharge Point 008

Year Round 5.z3

20. Pursuant to Water Code section 13385(j)(3), full compliance with the requirements of this TSO exempts the City from mandatory minimum penalties for violations of the final effluent limitations for ammonia in Order No. R4-2011-0196 that occur after the effective date of this TSO.

I

Year Round

21. This TSO includes interim requirements and the dates for their achievement. The interim requirements include both interim effluent limitations for ammonia and actions and milestones leading to compliance with the final effluent limitation for this pollutant.

l.13

22. Consistent with Water Code section 13385(j)(3)(C), the TSO requires compliance with effluent limitations for ammonia in Order No. R4-2011-0196 by September 30, 2017.

* Based on the result of 95 percentile, using Minitab. See calculation in Attachment A.

! City of Los Angeles Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

NPDES No. CA0056227

23. This TSO concerns the permitting of an existing facility and involves negligible or no expansion of use or other alternatives to the facility; is issued to assure the maintenance, restoration, enhancement, and protection of the environment; and is an administrative order enforcing waste discharge requirements. Therefore, issuance of this TSO is exempt from the provisions of the California Environmental Quality Act (Public Resources Code, Section 21 100, et.seq.) in accordance with sections 15301, 15308, and 15321(a)(2) of Title 14 of the California Code of Regulations.

24. The Regional Water Board has notified the City and interested agencies and persons of its intent to issue this TSO concerning compliance with waste discharge requirements. The Regional Water Board, during a public comment period and public hearing, received and considered all comments to this matter.

25. Any person aggrieved by this action of the Regional Water Board may petition the State Water Board to review the action in accordance with CWC section I3320 and CCR, title 23, sections 2050 and following. The State Water Board must receive the petition by 500 p.m., 30 days after the Regional Water Board action, except that if the thirtieth day following the action falls on a Saturday, Sunday, or state holiday, the petition must be received by the State Water Board by 500 p.m. on the next business day. Copies of the law and regulations applicable to filing petitions may be found on the Internet at http://www.waterboards.ca.c~ov/~ublic notices/petitions/water quality or will be provided upon request.

IT IS HEREBY ORDERED that, pursuant to Water Code sections 13300 and 13385(j)(3), the City of Los Angeles, as owner and operator of the Tillman WRP, shall comply with the requirements listed below to ensure compliance with the final effluent limitations for Ammonia contained in Order No. R4-2011-0196:

1. Comply immediately with the interim effluent limits in Table 4, which shall be deemed effective from the date of this Order until September 30, 2017, or until Order No. R4-2011-0196 has been revised to incorporate a revised LA River Nitrogen Compounds TMDL, whichever occurs sooner:

2. Achieve full compliance with the final effluent limitations as soon as possible, but no later than September 30, 2017, or comply with a revised NPDES permit for the Tillman WRP that incorporates a revised LA River Nitrogen Compounds TMDL adopted after the effective date of this TSO.

Table 4. Interim Ammonia Effluent Limitations

Constituent

Ammonia (year round)

Units

mg/L

Monthly Average

2.2


NPDES No. CA0056227

3. Submit quarterly progress reports of efforts taken by the City towards achieving compliance with the final effluent limits for ammonia. The reports shall summarize the progress to date, activities conducted during that quarter, and the activities planned for the upcoming quarters. The reports shall also state whether or not the Tillman WRP was in compliance with the interim effluent limitations for ammonia during the reporting period. Each quarterly report shall be received by the

1 Regional Water Board by the 15'~ day of the first month following the reporting I period (April 15, July 15, and October 15). The first progress report shall be

received by the Regional Water Board by April 15, 201 3, and will cover the months I of December 2012 through March 2013.

The progress reports shall detail any actions taken to support incorporation of the current Basin Plan ammonia and/or revisions to the 303(d) list, studies, facility modifications, and recommendations for additional measures, if necessary, to achieve full compliance with applicable final effluent limits. This TSO may be modified or rescinded upon a determination by the Executive Officer that the Discharger has failed to

I take actions or meet milestones necessary to comply with the effluent limits for ammonia I by September 30,2017.

I 4. Submit a pollution prevention plan workplan with a time schedule for implementation for approval of the Executive Officer within I 2 0 days of adoption of this TSO, pursuant to Water Code section 13263.3.

5. All technical and monitoring reports required under this TSO are required pursuant to Water Code sections 13267 and 13383. The Regional Water Board

1 needs the required information in order to determine compliance with this TSO and achievement of milestones towards compliance with the final effluent limitations in Order No. R4-2011-0196. The burdens, including costs, of these reports bear a reasonable relationship to the needs for the reports and the benefits to be obtained from the reports.

6. Any person signing a document submitted under this TSO shall make the I following certification:

"I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and

I belief, true, accurate, and complete. I am aware that there are significant 1 penalties for submitting false information, including the possibility of fine and

imprisonment for knowing violations."

7. If the City fails to comply with any provision of this TSO, the Regional Water Board may take any further action authorized by law. The Executive Officer, or hislher delegee, is authorized to take appropriate enforcement action pursuant, but not


NPDES No. CA0056227

limited to, Water Code sections 13350 and 13385. The Regional Water Board may also refer any violations to the Attorney General for judicial enforcement, including injunction and civil monetary remedies.

8. All other provisions of NPDES Order No. R4-2011-0196 not in conflict with this TSO are in full force and effect.

! 9. The Regional Water Board may reopen this TSO at its discretion or at the request

of the City, if warranted.

10. This TSO becomes effective immediately upon adoption by the Regional Water Board. This TSO expires on September 30, 201 7.

I, Samuel Unger, Executive Officer, do hereby certify that the foregoing is a full, true and correct copy of an order adopted by the Executive Officer pursuant to delegated authority by the California Regional Water Quality Control Board, Los Angeles Region, on December 6,2012.

1

l/l* Samuel ~ n g z , P.E. Executive Officer


NPDES No. CA0056227

Attachment A Calculation summary of lnterim Ammonia Limitation Using Los Angeles River Reaches 4 & 5 Site-Specific Objectives

I. Ammonia Site-Specific Objectives

A. For Discharge Points 001, 002, and 003 Located at Los Angeles River Reach 5 (Sepulveda Basin)

One-hour Average Objective = 0.41 1 + 58.4 1 + 107.204-pH 1 + 1 0 pH-7.204

... ... ... ..... Eq. 1

30-day Average Objective (from April I to September 30) =

0.0676 1 + 107.688-pH + 1 + 2'912 1 0 pH-7.688 ) * 0.854 * ~ 1 ~ ( 2 . 8 5 , 2.85 * 10°.028*(25-" ) ... ... .. . Eq. 2

30-day Average Objective (from October 1 to March 31) =

0.0676 1 + 107.688-p~ + 1 + 2m912 1 0 PH-7.688 ) * 0 . 8 5 4 * 2 . 8 5 * 1 0 ~ ~ ~ ~ ~ * ( ~ ~ - ~ " ~ ) ) ................ Eq. 3

Where T = temperature expressed in OC.

B. For Discharge Point 008 Located at Los Angeles River Reach 4 (Sepulveda Dam to Riverside Drive)

i

One-hour Average Objective = Eq. I

1 30-day Average Objective (year round) =

0.0676 + * 0.854 * 2-85 * 100.028*(25-MAXF,7) 1 + 107.688-pH 1 + 1 0 pH-7.688 ) . . . . . . . . . . . . . . . Eq. 4

' Where T = temperature expressed in OC.

I 11. ' Calculation, of Interim Ammonia Effluent Limitations at EfF-OOIA, Based on Effluent Data collected Between January 1, 2008 and March 31, 201 1

A. For Los Angeles River Reach 5 -

Only Eq. 1, Eq. 2, and Eq.3 are used to conduct the interim ammonia effluent limitations, because the Donald C. Tillman Water Reclamation Plant's Effluent Transfer Station Eff-001A via Discharge Points 001, 002, and 003 is located within Los Angeles River Reach 5.

A-I


1. Interim Ammonia Effluent Limitations from April I to September 30 for Early Life Stage (ELS) Present

Step I. - Identify applicable ammonia water quality Objectives (WQOs).

From the Discharger's effluent between April 1 and September 30, the following data are summarized below:

pH = 7.3 at 90th percentile (for One-hour Average Objective) pH = 7.25 at 50th percentile (for 30-day Average Objective) Temperature = 26.39 "C at 50th percentile (for 30-day Average 0 bjective)

When pH is equal to 7.3; One-hour Average Objective (Eq. 1) = 26.21 mg/L

When pH = 7.25 and temperature = 26.39 "C; 30-day Average Objective (Eq. 2) = 4.79 mg/L

From Basin Plan amendment;

4-day Average Objective = 2.5 times the 30-day average objective = 2.5 X 4.79 mg/L = 1 1.97 mg/L

Ammonia WQO Summary:

One-hour Average = 26.21 mg/L Four-day Average = 1 1.97 mg/L 30-day Average = 4.79 mg/L

Step 2 - For each water quality objective, calculate the effluent concentration allowance (ECA) using the steady-state mass balance model. Since mixing has not been allowed by the Regional Water Board, this equation applies:

ECA = WQO

Step 3 - Determine the Long-Term Average discharge condition (LTA) by multiplying each ECA with a factor (multiplier) that adjust for variability.

ECA multiplier when CV = 0.2796

ECA m ~ l t i p l i e r ~ - ~ , ~ , ~ ~ = 0.5486 ECA? m ~ l t i p l i e r ~ - ~ ~ ~ ~ ~ = 0.7306 ECA multiplier30-day99 = 0.8893

I City of Los Angeles Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

NPDES No. CA0056227

Using the LTA equations:

I LTAl-hour/gg = ECAl-hour x ECA multiplierl..hOur~~ = 26.21 mg/L x 0.5486 = 14.38 mg/L

LTA4-day/99 = EChmday X ECA = 11.97 mg/L x 0.7306 = 8.75 mg/L

LTA30-day/99 = ECA3~-day X ECA multiplier30-day99 = 4.79 mg/L X 0.8893 = 4.26 mg/L

Step 4 -- Select the (most limiting) of the LTAs derived in Step 3 (LTAmin)

Step 5 - Calculate water quality based effluent lim'itations for monthly average (AMEL,) and daily 'maximum (MDEL) by multiplying LTAmin as selected in Step 4 with a factor (multiplier).

Monthly sampling frequency (n) is 30 times per month or less, and the minimum LTA is the LTA30-day/991 therefore n = 30, CV = 0.2796.

AMEL m ~ l t i p l i e r ~ ~ = 1.0861 MDEL multipliergg = 1.8230

2. Interim Ammonia Effluent Limitations from October 1 to March 31 for ELS Absent

Step I. - Identify applicable ammonia WQOs.

From the Discharger's effluent between October 1 and March 31, the following data are summarized below: .

pH = 7.3 at 90th percentile (for One-hour Average Objective) pH = 7.2 at 50th percentile (for 30-day Average Objective) Temperature = 22.78 "C at 50th percentile (for 30-day Average Objective)

When pH is equal to 7.3; One-hour Average Objective (Eq. 1) = 26.21 mg/L


i City of Los Angeles Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

NPDES No. CA0056227

From Basin Plan amendment;

4-day Average Objective = 2.5 times the 30-day average objective = 2.5 X 6.22 mg/L = 15.55 mg/L


One-hour Average = 26.21 mg/L Four-day Average = 15.55 mg/L 30-day Average = 6.22 mg/L


ECA = WQO



ECA multiplierl~hourga = 0.6347 ECA m ~ l t i p l i e r ~ - ~ ~ ~ ~ ~ = 0.791 1 ECA m ~ I t i p l i e r ~ ~ - ~ ~ ~ ~ ~ = 0.9167


LTAl-hour/g9 = ECAl-hour x ECA multiplierl~hou,99 = 26.21 mg/L x 0.6347 = 16.64 mg/L

LT&dayigg = EChday X ECA r n ~ l t i p l i e r ~ - ~ , ~ ~ ~ = 15.55 mglL x 0.791 1 = 12.30 mg/L

LTA30-day/99 = ECA30-day X ECA m ~ l t i p l i e r ~ ~ - ~ , ~ ~ ~ = 6.22 mg/L x 0.91 67 = 5.70 mg/L


Step 5 - Calculate water quality based effluent limitations for monthly average (AMEL) and daily maximum (MDEL) by multiplying LTAmin as selected in Step 4 with a factor (multiplier).

Monthly sampling frequency (n) is 30 times per month or less, and the '

minimum LTA is the L T A ~ O - ~ ~ ~ / ~ ~ , therefore n = 30, CV = 0.2066.


NPDES No. CA0056227

AMEL multipliere5 = 1.0632 MDEL multipliergg = I .5756

B. For Los Angeles River Reach 4 -

Only Eq. 1 and Eq.4 are used to conduct the interim ammonia effluent limitations, because the Donald C. Tillman Water Reclamation Plant's Effluent Transfer Station Eff-001A via Discharge Point 008 is located within Los Angeles River Reach 4.

1 Year Round Interim Ammonia Effluent Limitations for ELS Absent

Step 1. - Identify applicable ammonia WQOs.

From the Discharger's effluent, the following data are summarized below:

pH = 7.3 at 90th percentile (for One-hour Average Objective) pH = 7.2 at 50th percentile (for 30-day Average Objective) Temperature = 25.00 "C at 50th percentile (for 30-day Average Objective)

When pH is equal to 7.3; One-hour Average Objective (Eq. I ) = 26.21 mg/L


I From Basin Plan amendment;



One-hour Average = 26.21 mg/L Four-day Average = 13.47 mg/L 30-day Average = 5.39 mg/L

Step 2 - For each water quality objective, calculate the effluent concentration allowance (ECA) using the steady-state mass balance


model. Since mixing has not been allowed by the Regional Water Board, this equation applies:

ECA = WQO



ECA m ~ l t i p l i e r ~ - ~ ~ ~ ~ ~ ~ = 0.5919 ECA m ~ l t i p l i e r ~ - ~ ~ ~ ~ ~ = 0.7618 ECA = 0.9037


LTAj-hour/gg = ECAlnour x ECA m ~ l t i p l i e r ~ - ~ ~ ~ ~ ~ ~ = 26.21 mg/L x 0.591 9 1 = 15.52 mg/L

LT&-day/99 = ECA4-day X ECA multiplier4-dayg9 = 13.47 mg/L x 0.761 8 = 10.26 mg/L

LTA30-day/99 = ECA30-day X ECA multiplier30-day99 = 5.39 mglL x 0.9037 = 4.87 mg/L



Monthly sampling frequency (n) is 30 times per month or less, and the minimum LTA is the LTA30-day/99, therefore n = 30, CV = 0.2409.

AMEL multipliers5 = 1.0740 MDEL multipliergg = 1.6893

Ill. Calculation of Interim Ammonia Effluent Limitations at Eff-OOIA, Based on Receiving Water Data Collected Between January 1, 2008 and March 31, 2011


NPDES No. CA0056227

The receiving water data collected between January 1, 2008 and March 31, 201 1 at Receiving Water Monitoring Station RSW-LATT630 (R-7) were used to conduct ammonia monthly effluent limitation. RSW-LATT630 (R-7) is located within Los Angeles River Reach 4, therefore, Eq. 1 and Eq.4 are used to conduct the interim ammonia effluent limitations.

A. For Los Angeles River Reach 4 -

I. Year Round Interim Ammonia Effluent Limitations for ELS Absent

Step I. - Identify applicable ammonia WQOs.

From the Discharger's effluent, the following data are summarized below:

1

pH = 8.47 at 90th percentile (for One-hour Average Objective) pH = 8.20 at 50th percentile (for 30-day Average Objective) Temperature = 19.63 "C at 50th percentile (for 30-day Average

, Objective) i

When pH is equal to 8.47; One-hour Average Objective (Eq. I ) ='3.37 mg/L

When pH = 8.20 and temperature = 19.63 "c; 30-day Average Objective (Eq. 3) = 2.54 mg/L

From Basin Plan amendment; 1



One-hour Average = 3.37 mglL Four-day Average = 6.34 mg/L 30-day Average = 2.54 mg/L


ECA = WQO


i City of Los brngeles Donald C. Tillman Water Reclamation Plant Time Schedule Order No. R4-2012-0180

ECA multiplier when CV = 0.71 65 I

NPDES No. CA0056227

ECA m ~ l t i p l i e r ~ . . ~ ~ ~ ~ ~ ~ = 0.2753 ECA m ~ l t i p l i e r ~ - ~ ~ ~ ~ ~ = 0.4734 ECA multiplier30-day99 = 0.7449


LTAl-hour,99 = ECAl-ho,r x ECA m ~ l t i p l i e r ~ ~ ~ ~ ~ , ~ ~ = 3.37 mg/L x 0.2753 = 0.93 mg/L

LT&-day/99 = EC&-day X ECA m ~ l t i p l i e r ~ - ~ ~ , ~ ~ = 6.34 mg/L x 0.4734 = 3.00 mg/L

LTA30-day/99 = ECA30-day X ECA multiplier30-day99 = 2.54 mg/L X 0.7449 = 1.89 mg/L



Monthly sampling frequency (n) is 30 times per month or less, and the minimum LTA is the LTA30-day/99r therefore n = 30, CV = 0.7165.

AMEL multiplier95 = 1.2285 MDEL multipliergg = 3.6330

AMEL = LTAmin x AMEL multiplierg5 = 0.93 mg/L x 1.2285 = 1 . I4 mgll r I. I mglL

AMEL = LTAmin x AMEL multipliergg = 0.93 mg/L x 3.6330 = 3.37 mg/l z 3.3 mglL

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CALIFORNIA w Water Boards ENVIRONMENTAL PROTECTION€¦ · CALIFORNIA w Water Boards ENVIRONMENTAL PROTECTION Los Angeles Regional Water Quality Control Board December 10,2012 Mr